Manizales is a decent, fairly pleasant city - rare for a city of its size in Colombia. Strangely for a small city in Colombia, it also has a number of universities.

Unfortunately, none of the universities in Manizales is particularly good, meaning that even if they were to hire you, the salary probably wouldn't be very high. I went there several years ago to pass my resume to the majority of the universities around the city and never heard anything back from any of them. My guess is they don't really hire foreigners, except through the British Council's language assistant program.

There's probably a small handful of high schools that would hire foreigners and pay somewhere around $3 million pesos/month...my best guess is that in a city like Manizales you might have about 5 high schools that fall into this category. No idea which schools these would be. My recommendation would be to talk to people in Manizales and ask where the rich kids study.